This proposal describes a 5 year training program designed to facilitate the ability of the candidate to pursue an independent career in the field of pleural fibrosis. The candidate came to The University of Texas Health Science Center at Tyler as a post-doctoral fellow, has joined the faculty as an Assistant Professor of Biochemistry and will continue his transition to independence through comprehensive mentorship and by conducting a completely novel, high impact scientific project. This program will shed new light on the pathogenesis of pleural fibrosis, which affects thousands of patients annually and for which treatment options are invasive or of uncertain benefit. In work reported by this laboratory, the mesothelium has previously been shown to promote fibrotic repair by promoting local procoagulant activity and suppressing fibrinolysis in the pleural compartment. The mesothelium can also support pleural organization and unrestricted repair via phenotypic changes of mesothelial cells; mesomesenchymal transition (MT). Our preliminary data support the concept that procoagulants induce MT. The role of factor Xa and thrombin in MT is now unknown and will be elucidated in this project. Dr. Steven Idell will serve as the primary mentor for the principal investigator's scientific development. Dr. Idell is a leader in the field of coagulation nd fibrinolysis in lung and pleural injury who has a long-standing interest in the treatment of pleura fibrosis. He is the Vice President for Research at The University of Texas Health Science Center at Tyler (UTHSCT) and has mentored numerous successful trainees. An advisory committee including Dr. Hua Tang and Dr. Sreerama Shetty resident experts in the field of lung fibrosis and Dr. L. Vijaya Rao a world renowned expert in the field of coagulation will mentor the applicant. They will ensure that the applicant achieves his objective of becoming a successful independent investigator. Our hypothesis is that factor Xa and thrombin are important determinants of MT and pleural fibrosis. Our objective is to elucidate the contribution of coagulation proteases to MT and the development of pleural loculation and fibrosis that follow acute pleural injury. The Specific Aims of the proposal are: 1) to determine the mechanism of FXa and thrombin mediated MT in pleural mesothelial cells, 2) to elucidate the role of Akt and Wnt/-catenin-signaling in FXa and thrombin mediated-MT in PMCs, and 3) to determine the role of FXa and thrombin in evolving fibrosing pleural injury in mice. To accomplish this work, a number of techniques, including cell biology, immunologic, protein chemistry and molecular biology techniques will be used. The Biomedical Research Department of UTHSCT is an ideal setting to conduct this research project. The combination of strong institutional support and an enthusiastic, productive advisory committee provides a nurturing environment that will enable the applicant to accelerate his successful transition to an independent investigative career. (End of Abstract)